Disordered leptin and ghrelin bioactivity in adolescent idiopathic scoliosis (AIS): a systematic review and meta-analysis

Association between the GLP1R A316T Mutation and Adolescent Idiopathic Scoliosis in French Canadian and Italian Cohorts

Studies have revealed anthropometric discrepancies in girls with adolescent idiopathic scoliosis (AIS) compared to non-scoliotic subjects, such as a higher stature, lower weight, and lower body mass index. While the causes are still unknown, it was proposed that metabolic hormones could play a role in AIS pathophysiology. Our objectives were to evaluate the association of GLP1R A316T polymorphism in AIS susceptibility and to study its relationship with disease severity and progression. We performed a retrospective case-control association study with controls and AIS patients from an Italian and French Canadian cohort. The GLP1R rs10305492 polymorphism was genotyped in 1025 subjects (313 non-scoliotic controls and 712 AIS patients) using a validated TaqMan allelic discrimination assay. Associations were evaluated by odds ratio and 95% confidence intervals. In the AIS group, there was a higher frequency of the variant genotype A/G (4.2% vs. 1.3%, OR = 3.40, p = 0.016) and allele A (2.1% vs. 0.6%, OR = 3.35, p = 0.017) than controls. When the AIS group was stratified for severity (≤40° vs. >40°), progression of the disease (progressor vs. non-progressor), curve type, or body mass index, there was no statistically significant difference in the distribution of the polymorphism. Our results support that the GLP1R A316T polymorphism is associated with a higher risk of developing AIS, but without being associated with disease severity and progression.

Current biomechanical theories on the etiopathogenesis of idiopathic scoliosis

PURPOSE

There is great controversy about the etiologic origin of adolescent idiopathic scoliosis. Multiple theories have been suggested, including metabolic aspects, endocrine dysfunction, neurological central abnormalities, genetic predisposition and epigenetic factors involved in the development of scoliosis. However, there has always been speculations based on human biomechanical behavior.

METHODS

In this article, we performed a literature review on the biomechanical traits of human posture, and the proposed theories that explain the special characteristics present in idiopathic scoliosis.

RESULTS

The current theory on the etiopathogeneis of AIS suggests that dorsally directed shear loads acting on a preexisting axial plane rotation, in a posteriorly inclined sagittal plane of a growing patient, together with disc maturation, collagen quality at this phase of development and immaturity of proprioception, is the perfect scenario to spark rotational instability and create the three-dimensional deformity that defines idiopathic scoliosis.

CONCLUSION

The unique spinal alignment of human bipedalism, gravity and muscle forces acting straight above the pelvis to preserve an upright balance, and the instability of the soft tissue in a period of growth development, is an appealing cocktail to try to explain the genesis of this condition in humans.

Association of polymorphism in leptin receptor gene with susceptibility of adolescent idiopathic scoliosis

PURPOSE

Abnormal leptin bioavailability has play key roles in the etiology of adolescent idiopathic scoliosis (AIS). Both leptin and its receptor levels may be modulated by the presence of genetic polymorphisms. This study aimed to evaluate the role of polymorphisms in the leptin (LEP) and its main receptor (LEPR) genes in the AIS susceptibility in girls.

METHODS

A retrospective case-control study was conducted with 189 AIS and 240 controls. LEP rs2167270 and LEPR rs2767485 polymorphisms were genotyped using a TaqMan validated assay. Associations were evaluated by odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

The AIS group showed a predominance of girls under 18 years old (n = 140, 74.1%), 148 (78.3%) had low or normal BMI, 111 (58.7%) had Cobb ≥ 45º and 130 (68.7%) were skeletally mature. Minor allele frequencies of rs2167270 and rs2767485 were 35.7% and 18.3%, for AIS and 35.6% and 25.4% for controls, respectively. LEPR rs2767485 T and TC + TT were associated with higher risk of AIS (OR = 1.53; 95% CI = 1.09-2.13 and OR = 1.84; 95% CI = 1.69-2.01, respectively), since CC genotype was only present in the control group. In addition, the LEP rs2167270 GA + AA was more frequent in low weight group (BMI ≤ 24.9) of girls with AIS. There was no significant association between LEP rs2167270 and AIS susceptibility, and LEPR rs2767485 and BMI.

CONCLUSION

The LEPR rs2767485 was associated with the genetic susceptibility of AIS and LEP rs2167270 with low BMI. These data can contribute to the identification of genetic biomarkers to improve the diagnosis and treatment.

Differences in Pubertal Curve Progression among Females with Adolescent Idiopathic Scoliosis Using Pregnenolone Therapy: A Retrospective Case-Controlled Series

Background: Differences in hormone metabolism have been observed in children with adolescent idiopathic scoliosis. These differences have been offered as underlying reasons for rapid curve progression during puberty. This study retrospectively compared two groups of females with a history of adolescent idiopathic scoliosis. They were seen for initial presentation prior to menarche, or within 2 months after menarche, and they were followed up 1 year after first menarche. Methods: All patients in both groups underwent baseline salivary hormone testing to identify any hormone imbalances. The control group was composed of females with curves between 10 and 25 degrees and maintained an observation-only management strategy. The treatment group showed baseline curve measurements ranging from 10 to 23 degrees, and additionally took pregnenolone daily for 12 months. Results: At one-year follow-up, the treatment group showed curve measurements ranging from 13 to 24 degrees, while the control group ranged from 16 to 29 degrees (p < 0.05). Conclusions: The study showed that adolescent females taking pregnenolone daily for low progesterone had reduced scoliosis curve progression over 1 year compared to controls.

The Role of Muscle Biomarkers in Adolescent Idiopathic Scoliosis

Adolescent idiopathic scoliosis (AIS) is the predominant orthopedic disorder in children, affecting 1-3% of the global population. Research in this field has tried to delineate the genetic factors behind scoliosis and its association with heredity since AIS is considered a polygenic disease and has different genetic and epigenetic factors. The current study conducted a narrative review of the literature, focusing on biomarkers in the pathophysiology of muscle in AIS patients. Articles were collected from Scopus, Pubmed, and Web of Science. The key screening parameters were scoliosis classification, sampling, and the biomarkers evaluated. This review emphasizes potential key mechanisms and molecular regulators in muscle tissue. While there has been limited focus on the proteins contributing to muscle changes in AIS, significant attention has been given to genomic studies of single-nucleotide polymorphisms, particularly in LBX1. Despite these efforts, the exact causes of AIS remain elusive, with several theories suggesting genetic and hormonal factors. This review identified critical protein biomarkers such as Gi-protein alpha subunits, fibrillin-1 and -2, and various differentially expressed proteins, which may be linked to muscle alterations in AIS. This field of research is still limited due to a lack of homogeneity in the distinction of patients by groups and curve severity. Although the pathophysiology of AIS is still unclear, molecular research is important to guide the treatment of AIS before achieving skeletal maturity, thus avoiding serious problems associated with posture changes and low quality of life. In the future, a more comprehensive synergy between orthopedic and molecular research might ameliorate the diagnosis and treatment of AIS patients.

Interaction between Selected Adipokines and Musculoskeletal and Cardiovascular Systems: A Review of Current Knowledge

Adipokines are substances secreted by adipose tissue that are receiving increasing attention. The approach to adipose tissue has changed in recent years, and it is no longer looked at as just a storage organ but its secretion and how it influences systems in the human body are also looked at. The role of adipokine seems crucial in developing future therapies for pathologies of selected systems. In this study, we look at selected adipokines, leptin, adiponectin, chemerin, resistin, omentin-1, nesfatin, irisin-1, visfatin, apelin, vaspin, heparin-binding EGF-like growth factor (HB-EGF), and TGF-β2, and how they affect systems in the human body related to physical activity such as the musculoskeletal and cardiovascular systems.

Incidence of vitamin D deficiency in adolescent idiopathic scoliosis: a meta-analysis

Introduction

This study aimed to investigate the incidence of vitamin D deficiency in patients with adolescent idiopathic scoliosis through a meta-analysis and to analyze trends and risk factors.

Methods

Potentially relevant studies were searched using the terms "Vitamin D AND scoliosis." Data on the incidence and risk factors, such as race, curve magnitude, and sex, were extracted from the selected studies. Review Manager 5.4 software was used for the data analysis. Six studies with a total of 1, 428 patients met the inclusion criteria.

Results

The incidence of vitamin D insufficiency in patients with idiopathic scoliosis was 36.19% (95% CI [21.93 to 50.46]. In contrast, the incidence of vitamin D deficiency was 41.43% (95% CI [16.62 66.23]. Vitamin D levels were compared between Caucasian and African patients and it was concluded that Caucasian patients had a lower risk of vitamin D deficiency [RR 0.15, 95% CI (0.03 to 0.82; P = 0.03]. There was also an association between patients with idiopathic scoliosis and lower vitamin D -5.58, 95% CI [-7.10, -4.06]. Finally, no significant differences were observed in terms of curve magnitude assessed with the Cobb angle mean difference (MD) 4.45, 95% CI [-0.55, 9.44], or sex with lower-than-normal levels of vitamin D OR 0.96, 95% CI [0.58 to 1.60].

Discussion

The incidence rates of vitamin D insufficiency and deficiency in patients with adolescent idiopathic scoliosis were 36.19% and 41.43%, respectively. The Caucasian race was associated with a lower risk of vitamin D deficiency compared to the African race. Vitamin D deficiency was not related to curve magnitude or sex.

Metabolic Imbalances and Bone Remodeling Agents in Adolescent Idiopathic Scoliosis: A Study in Postmenarcheal Girls

The causes and mechanisms underlying adolescent idiopathic scoliosis (AIS) remain unclear, and the available information regarding metabolic imbalances in AIS is still insufficient. This investigation aimed to evaluate the concentrations of specific bone remodeling-related agents in postmenarcheal girls diagnosed with AIS. The study encompassed thirty-six scoliosis patients and eighteen age-matched healthy individuals assigned to the control group. The patients underwent clinical and radiological examinations to assess the degree of the spinal deformity, type of curvature, and skeletal maturity. Blood and urine samples were collected from all participants and serological markers were measured using an enzyme-linked immunosorbent assay. Our study results demonstrated that the balance of phosphate-calcium and parathormone levels seems normal in individuals with AIS. Furthermore, no statistically significant differences were observed in the content of Klotho protein, osteocalcin, osteoprotegerin, C-terminal telopeptide of type I collagen (CTX), sclerostin, and alkaline phosphatase. Nevertheless, the serum levels of vitamin D (25-OH-D) were lowered, while N-terminal propeptide of type I procollagen (PINP), and fibroblast growth factor-23 (FGF23) were increased in the AIS group, with p-values of 0.044, 0.001, and 0.022, respectively. This finding indicates the potential involvement of these factors in the progression of AIS, which necessitates further studies to uncover the fundamental mechanisms underlying idiopathic scoliosis.

What is New in Pediatric Orthopaedic: Basic Science

BACKGROUND

An understanding of musculoskeletal basic science underpins most advancements in the field of orthopaedic surgery. Knowledge of biomechanics, genetics, and molecular pathways is integral to the understanding of the pathophysiology of disease and guides novel treatment options to improve patient outcomes. The purpose of this review is to provide a comprehensive and current overview of musculoskeletal basic science relevant to pediatric orthopaedic surgery.

METHODS

Comprehensive Pubmed database searches were performed for all English language articles published between January 2016 and November 2021 using the following search terms: basic science, pediatric orthopaedics, fracture, trauma, spine, scoliosis, DDH, hip dysplasia, Perthes, Legg-Calve-Perthes, clubfoot, and sports medicine. Inclusion criteria focused on basic science studies of pediatric orthopaedic conditions. Clinical studies or case reports were excluded. A total of 3855 articles were retrieved. After removing duplicates and those failing to meet our inclusion criteria, 49 articles were included in the final review.

RESULTS

A total of 49 papers were selected for review based on the date of publication and updated findings. Findings are discussed in the subheadings below. Articles were then sorted into the following sub-disciplines of pediatric orthopaedics: spine, trauma, sports medicine, hip, and foot.

CONCLUSIONS

With this review, we have identified many exciting developments in pediatric orthopaedic trauma, spine, hip, foot, and sports medicine that could potentially lead to changes in disease management and how we think of these processes.

LEVEL OF EVIDENCE

Level V.

Risk factors associated with low bone mineral density in children with idiopathic scoliosis: a scoping review

BACKGROUND

Children with idiopathic scoliosis (IS) have a high risk of osteoporosis and IS with low bone mineral density (BMD) are susceptible to curve progression. This review aims to explore the risk factors of low BMD in children with IS.

METHODS

Studies were retrieved from 5 databases that were published up to January 2022. Search terms are keywords in titles or abstracts, including subject headings related to "Scoliosis", "Bone Mineral Density", and "Risk Factors". Observational studies on risk factors of low BMD in children with IS were enrolled in this review. The number of studies, sample size, outcome measures, research type, endocrine, and lifestyle-related factors, gene/signal pathway, and other contents were extracted for qualitative analysis.

RESULTS

A total of 56 studies were included in this scoping review. Thirty studies involved genetic factors that may affect BMD, including the Vitamin-D receptor gene, RANK/RANKL signal pathway, the function of mesenchymal stem cells, Runx2, Interleukin-6 (IL-6), and miR-145/β-catenin pathway. Eight studies mentioned the influence of endocrine factors on BMD, and the results showed that serum levels of IL-6, leptin and its metabolites, and ghrelin in children with IS were different from the age-matched controls. In addition, there were 18 articles on lifestyle-related factors related to low BMD in children with IS, consisting of physical activity, calcium intake, Vitamin D level, and body composition.

CONCLUSIONS

Genetic, endocrine, and lifestyle-related factors might relate to low BMD and even osteoporosis in IS. To prevent osteoporosis, the effectiveness of regular screening for low BMD risk factors in children with IS needs to be investigated. Additionally, clear risk factors suggest strategies for bone intervention. Future studies should consider the effectiveness of calcium and vitamin D supplements and physical activity in BMD improvement.

Circulatory Adipokines and Incretins in Adolescent Idiopathic Scoliosis: A Pilot Study

Adolescent idiopathic scoliosis (AIS) is a three-dimensional malformation of the spine of unknown cause that develops between 10 and 18 years old and affects 2-3% of adolescents, mostly girls. It has been reported that girls with AIS have a taller stature, lower body mass index (BMI), and bone mineral density (BMD) than their peers, but the causes remain unexplained. Energy metabolism discrepancies, including alterations in adipokine and incretin circulatory levels, could influence these parameters and contribute to disease pathophysiology. This pilot study aims to compare the anthropometry, BMD, and metabolic profile of 19 AIS girls to 19 age-matched healthy controls. Collected data include participants' fasting metabolic profile, anthropometry (measurements and DXA scan), nutritional intake, and physical activity level. AIS girls (14.8 ± 1.7 years, Cobb angle 27 ± 10°), compared to controls (14.8 ± 2.1 years), were leaner (BMI-for-age z-score ± SD: -0.59 ± 0.81 vs. 0.09 ± 1.11, p = 0.016; fat percentage: 24.4 ± 5.9 vs. 29.2 ± 7.2%, p = 0.036), had lower BMD (total body without head z-score ± SD: -0.6 ± 0.83 vs. 0.23 ± 0.98, p = 0.038; femoral neck z-score: -0.54 ± 1.20 vs. 0.59 ± 1.59, p = 0.043), but their height was similar. AIS girls had higher adiponectin levels [56 (9-287) vs. 32 (7-74) μg/mL, p = 0.005] and lower leptin/adiponectin ratio [0.042 (0.005-0.320) vs. 0.258 (0.024-1.053), p = 0.005]. AIS participants with a Cobb angle superior to 25° had higher resistin levels compared to controls [98.2 (12.8-287.2) vs. 32.1 (6.6-73.8), p = 0.0013]. This pilot study suggests that adipokines are implicated in AIS development and/or progression, but more work is needed to confirm their role in the disease.

An Assessment of the Relationship between BMI and Children Undergoing Surgical Procedures: A Retrospective Study

Background: While multiple studies have documented that obesity increases the risk of operative complications among adults, little data exist on how obesity impacts surgical outcomes among children. We aimed to determine if children with obesity have different postoperative outcomes than their peers. Methods: A retrospective chart review was conducted of 875 patients aged between 2 and 18 years who underwent surgery during 2018. Patients were stratified, based on BMI percentile for age, as having less than healthy weight (<5th percentile), healthy weight (5th-84th percentile), excess weight (85th-94th percentile), or obesity (≥95th percentile). Demographic information and data on medical comorbidities and postoperative complications were collected. All analyses were conducted using chi-square or Kruskal-Wallis testing. Results: Eighty-two patients were excluded due to lack of BMI data and 56 were excluded as they had below healthy weight. Of the remaining 737 patients, 475 (64.4%) had healthy weight, 124 (16.8%) had excess weight, and 138 (18.70%) had obesity. Children with obesity had more tonsillectomy/adenoidectomy (p < 0.01) and vascular access (p = 0.04) procedures compared with peers. Additionally, patients with obesity were more likely to have a pre-existing history of liver disease (p < 0.01) and more frequently developed postoperative wound dehiscence (p < 0.01). No other complications occurred more frequently among children with obesity. Conclusions: Children with obesity required more tonsillectomy/adenoidectomy and vascular access procedures. Wound dehiscence was the only complication that was associated with obesity. This suggests that children with obesity are not inherently more prone to experience surgical complications and therefore elective procedures should likely not be deferred until preoperative weight loss is achieved.

Salivary Progesterone Levels in Female Patients with a History of Idiopathic Scoliosis: A Retrospective Cross-Sectional Study

Idiopathic scoliosis is a condition characterized by a three-dimensional curvature of the spine. However, in addition to the spinal curvature, it has also been reported that patients with idiopathic scoliosis can display other abnormal physiologic parameters, such as hormone imbalances, genetic variants, and micronutrient deficiencies. The present study evaluates the salivary progesterone levels from a historical cohort of patients seeking treatment at a single integrative medicine clinic. A group of female patients with a history of idiopathic scoliosis is compared to a group of non-scoliosis female patients. Salivary progesterone levels were 49% higher in non-scoliosis patients compared to the scoliosis group (p < 0.05). When compared by the menstrual cycling status, non-scoliosis females had a 60% higher average progesterone level, while the progesterone level among non-cycling, non-scoliosis females was 39% higher than non-cycling scoliosis females. These results suggest a potential relationship between salivary progesterone and idiopathic scoliosis among female patients.

The role of endocrine hormones in the pathogenesis of adolescent idiopathic scoliosis

Adolescent idiopathic scoliosis (AIS) is a common spinal deformity characterized by changes in the three-dimensional structure of the spine. It usually initiates during puberty, the peak period of human growth when the secretion of numerous hormones is changing, and it is more common in females than in males. Accumulating evidence shows that the abnormal levels of many hormones including estrogen, melatonin, growth hormone, leptin, adiponectin and ghrelin, may be related to the occurrence and development of AIS. The purpose of this review is to provide a summary and critique of the research published on each hormone over the past 20 years, and to highlight areas for future study. It is hoped that the presentation will help provide a better understanding of the role of endocrine hormones in the pathogenesis of AIS.

Is ghrelin a biomarker of early-onset scoliosis in children with Prader-Willi syndrome?

Background

Adolescents with idiopathic scoliosis display high ghrelin levels. As hyperghrelinemia is found in patients with PWS and early-onset scoliosis (EOS) is highly prevalent in these patients, our aims were to explore (1) whether ghrelin levels differ between those with and without EOS and correlate with scoliosis severity, and (2) whether ghrelin levels in the first year of life are associated with the later development of EOS.

Methods

We used a case control study design for the first question and a longitudinal design for the second. Patients with PWS having plasma ghrelin measurements recorded between 2013 and 2018 in our database were selected and 30 children < 10 years old with EOS and 30 age- and BMI-matched controls without EOS were included. The Cobb angle at diagnosis was recorded. In addition, 37 infants with a ghrelin measurement in the first year of life were followed until 4 years of age and assessed for EOS. Total ghrelin (TG), acylated (AG) and unacylated ghrelin (UAG), and the AG/UAG ratio were analyzed.

Results

EOS children had an AG/UAG ratio statistically significantly lower than controls. The Cobb angle was positively correlated with TG and UAG. TG and AG in the first year of life were higher in infants who later develop EOS without reaching a statistically significant difference.

Conclusions

Our results suggest that ghrelin may play a role in the pathophysiology of EOS in PWS. Higher ghrelinemia in the first year of life required careful follow-up for EOS.

Low Body Mass Index Levels and Idiopathic Scoliosis in Korean Children: A Cross-Sectional Study

BACKGROUND

The prevalence of idiopathic scoliosis is rapidly increasing in Korean children, but research on the disorder is limited compared to that in other countries. Accordingly, in the present study, we aimed to investigate the relationship between idiopathic scoliosis and body mass index (BMI) levels in Korean children.

METHODS

This cross-sectional study enrolled elementary school students and middle school first graders in the Capital Area in Korea. The participants underwent body composition measurements and screening for idiopathic scoliosis. Idiopathic scoliosis was defined as a Cobb angle of ≥10°. The students were classified into three groups-the severely underweight (SUW: BMI < 16 kg/m2) group, the underweight group (UW: 16 ≤ BMI < 18.5 kg/m2), and the normal weight group (NW: 18.5 ≤ BMI < 25 kg/m2) to compare the risk of idiopathic scoliosis across BMI levels.

RESULTS

The final cohort comprised 1375 participants. The odds ratio (OR) of idiopathic scoliosis was 0.69 (95% confidence interval (CI): 0.50-0.94) and 0.66 (95% CI: 0.49-0.89) for the UW and the NW groups, respectively, with the SUW group as the reference. This shows that the risk decreased significantly by 31% and 34% in the UW and the NW groups, respectively. After controlling for age and sex, the corresponding ORs were 0.72 (95% CI: 0.52-0.98) and 0.70 (95% CI: 0.51-0.96), and the risk significantly decreased by 28% and 30% in the UW and the NW groups, respectively.

CONCLUSIONS

Low body weight is closely associated with spinal deformity and idiopathic scoliosis.

Effects of myofascial release or self-myofascial release and control position exercises on lower back pain in idiopathic scoliosis: A systematic review

BACKGROUND

Idiopathic scoliosis is associated, among others, to muscular imbalance, functional limitations, and the most prevalent, back pain. The treatments usually applied are exercise, bracing or surgery. The objective of corrective exercise is to reduce symptoms and improve functional capacity and quality of life. Myofascial release (MFR) or Self-Myofascial release (SMFR) are manual techniques, intended to restore optimal muscle and fascia length, decrease pain, and improve function.

PURPOSE

to analyze the effects of MFR and postural control programs in lower back pain and scoliosis curves.

METHODS

A systematic literature review was conducted in high quality databases to identify the existing evidence of the effects of MFR and postural control on reducing back pain and scoliosis curves.

RESULTS

Seventeen studies met inclusion criteria. 533 subjects and 94 MFR/SMFR applied interventions lasting one to 24 weeks/sessions were identified. Ten studies used MFR, six SMFR and one mixes techniques. Seven MFR and five SMFR studies shown positive result. One study using MFR and one using SMFR applied also postural control exercises. MFR was useful to reduce back pain in all studies included that aimed in that matter. In addition, 12 studies reported improvements in flexibility and/or stiffness reduction, and two studies observed improvements in postural control and balance.

CONCLUSIONS

The combination of MFR and postural control programs might be suitable for reducing scoliosis and back pain. However, due to the reduced number of studies and the relatively small sample sizes used, results may be carefully interpreted, and more studies are needed.